Robinson R22 Beta, G-CDBG and Robinson R44 Astro, G-OLOW

Summary:

On the morning of the accident a pilot parked an R22 at the refuelling area. Later another pilot parked an R44 next to the R22. Later in the morning the pilot/instructor of the R22 who had earlier parked the R44 next to the R22, briefed his student to go out and pre-flight and start-up the R22. Just prior to lift off there was a sudden bang and a massive vertical vibration. The main rotor blades had contacted those of the R44 which had just started up. The pilot/instructor, who had parked the R22 earlier in the morning, was tasked to fly the R44 with another pilot for a conversion flight. The conversion pilot carried out the external pre-flight check. As part of this check he rotated the main rotor blades through 180° to ensure that there was sufficient tip clearance from the adjacent R22. At this time the R22 had not been started up. The instructor returned, completed the internal checks and proceeded to start the R44 when the main rotor blades contacted those of the now running R22. Since this accident the operator has painted measured parking spots in the refuelling area